Recipe for low-cost medical tests: FISH and chips

Ultra-expensive medical tests such as fluorescence in situ hybridization (FISH) provide early warnings for a variety of diseases that can be cured if caught in time. Unfortunately, only the wealthy can routinely have them performed, because the reagents used in such tests can cost as much as $1 million per gram.

Now an electrical engineer at the University of Alberta [http://www.ualberta.ca/] (Edmonton, Canada) has designed a programmable microfluidic chipreminiscent of the Star Trek "tricorder"that performs FISH and similar tests with a fraction of the reagents normally required. That can speed the time-to-results by at least tenfold and cut the costs from as much as $1,000 to as low as a dollar.

"Our microfluidic system allows us to process extremely small quantities of reagents," said professor Chris Backhouse. "The small quantities we use decrease both the cost and the time by a factor of 10 to 1,000, depending on the particular test being performed."

The handheld device employs a novel method to immobilize blood cells inside its microfluidic channels using both mechanical and electrokinetic pumping. FISH and other sensitive diagnostic tests performed by these microfluidic chips can detect the telltale signs of many aggressive diseases on a cell-by-cell basis.

In the past, the high cost and slow turnaround of such tests have discouraged their routine use in clinical settings. But Backhouse, working with University of Alberta oncology professor Linda Pilarski, has developed a variety of microfluidic chips to perform such tests via handheld devices for a fraction of the cost of traditional tests. Specifically, using these chips, test results can be obtained 10 times faster and 10 times more cheaply, which the researchers hope to eventually improve to 1,000 times faster and cheaper.

"We are trying to build tricorders, like they have on Star Trek, which give inexpensive results immediately," said Backhouse. "A tricorder for the life sciences must perform many sequential steps, each of which takes hours to perform by a human, which can add up to several days to get the full results back. However, with our microfluidic chips, we can reduce that time to a couple of hours."

Backhouse added that "large companies like Siemens and Philips are starting to get interested in microfluidic devices like ours. In fact, the whole field of life sciences is getting more interested in applied electronics. It is a very interesting time to be an electrical engineer."

Currently, Backhouse and Pilarski's microfluidic chips are being tested in a clinical setting at the Cross Cancer Institute (Edmonton) as part of the Alberta Cancer Diagnostics Consortium (ACDC), an initiative to commercialize the chips for diagnostics.